Tube sheet



April 29, 1930. c. w. GORDON TUBE SHEET Filed Jan. 4. 1929 1 N V EN TOR.C//z 5 14. a 'a n.

A TTORNE Y.

Patented Apr. 29, 1 930 UNITED, STATES PAT Nr *OFFICE CHARLES WQGORDON,OF PLEASANTVILJE, YORK, ASSIGNOR TO THE HEATEB COMPANY.

TUBE

or NEW YORK, N. a'. 4

samir Application filed January 4, 1929. Serial No. 330,179.

tion is equally well applicable to other types of apparatus.

Fig. 1 is generally a vertical longitudinal section through a locomotivetype feed water heater, the right half being a true section, the lefthalf showing the shell in section and the parts within the shell partlyin elevation and partly in central-vertical section; Fig. 2 is an endelevation looking from the right of Fig. l; and Figs. 3 and 4 are planand elevational views respectively of the improved form of tube sheetemployed.

Referring' now to Fig. 1, the heater comprises a cylindrical casing 1closed at one end by tube sheet 2 and at the other end by the cap orcover plate 3. A plurality of tubes 4 are expanded at, one end into tubeholes 5 in tube sheet 2, which, as will be evident from Fig. 3, aredivided into a number of spaced' groups for a purpose which will becomeclear later.

At their other ends, tubes i are expanded into semi-circular tube sheets6and'7, these tube sheets being separated diamet-rically along the planeof the paper in Fig. 1" and frecly movable with respect to each otherand .the casing 1 to allow for expansion of the tubes 4. As viewed inFig. 1 the curved front edge of the tube sheet 6 is seen, while the partof 7 which is seen is' the straight vertical edge.

The semircircular headers 8 and 9 are secured respectively to the outerfaces of semi-circular tube sheets 6 and 7. Of these' headers, the upperpart of' the figure shows the front 'rounded surface of' the frontheader, and at the lower part 'of the figure the Vertical flat surfaceof the rear header is seen.

-The fixed tube sheet 2 has bolted to its outer face a semi-circularheader 10 and a pair of quarter-circular headers ll and 12, header 11beingprovided with an inlet connection 13 and header 12 being providedwith a similar outlet connection 14.

As previously noted, the semi-circular headers 8 and 9 are bolted to tbesleets 6 and 7 with the 'line of division vertical, while as* shown moreclearly in Fig. 2 the line of division between header 10 'and headers 11and 12 is horizontal and the line of division between headers 11 and 12is vertical.

With this arrangement of the headers it will be readily apparent thatfour passes through the bundle of tubes 4 are provided. Assuming theinlet to be through connection SUPER- 13, the first pass is through thegroup of tubes i covered by header 11, thence upwardly through semi-circlar header 8, back through the tubes connecting the upper end of header8 with the left-hand side of header 10, thence through header 10 and thetubes covered by the right half thereof to the upper end of.

header 9, downwardly through header 9 and finally back through the tubesconnecting the lower end of header 9 with the quarter-header 12.

Inlets 15 are provided in casing 1 fol-the I adnission of steam or otherheating medium, and a dran 16 s provided for the removal of condensate,

The structure so far described is not novel,

and prior to my invention considerable difficulty has been encounteredin *maintaining a joint between tube sheet 2 and the headers Securedthereto which would remain tight under a fluid pressure .of highmagnitude such as that encountered when the heater is located between aboiler feed pump and the boiler. For this articular class of service' ametal to metal ]0l1t has been found more satisfactory than any knownformof packed or gasket joint, and in the-heretofore best 'known practicethe outer face of tube sheet 2 is finished to an accurate plane surface,as are the bottoms of the headers to be Secured thereto, and the headersand tube sheet as sembled by direct bolting of the headers to the tubesheet without the use of any gasket or packing at the joint.

u groove may vary between wide limits with Experience has shown,however, that while a single header may be satisfactorily bolted to atube sheet as, for example the bolting of headers 8 and 9 to the tubesheets 6 and 7 and a tight joint maintained, leakage occurs if it isattempted to bolt a plurality of headers to a single integral tubesheet. Taking the header and tube sheet assembly shown in Fig. 2 ..forexample, the header 10 can be bolted to the tube sheet and a tight jointmaintained as long as the adjacent headers 11 and 12 are not bolted tothe tube sheet, but upon the latter being bolted to the tube sheet anddrawn to a tight seat, the header 10 will almost invariably developleaks at points 10"' and 10 which cannot be eliminated even by theapplication of the utmost permissible pressure to the header throughdrawing up of the bolts securing it to the tube sheet.

Although I do not desire to be in any way bound by such theory, it is mybelief that this leakage is caused by the fact that the bolting ofheaders 11 and 12 to the face of the tube sheet sets up therein a fibreStress which is transmitted through the tube sheet in a manner whichdistorts the latter and results in a non-plane surface under thesemi-circular header 10. The latter is necessarily extremely stifl" inorder to withstand the internal pressure exerted thereon in service, andits form, moreover, is such that it is extremely rigid so that it cannotbe distorted by pressure apdepth of the groove is preferably at leastone- While in the preferred form illustrated I plied through thesecuring bolts sufficiently to make it follow a non-plane tube sheetsurface.

I have successfully overcome the difliculty -due to the above phenomenonby providing a rabbeted groove 17 in the outer face of the tube sheet.between the half header 10 and the quarter headers' 11 and 12. Thedepth of this groove and the inner face of the tube sheet..

as representedby' 17' necessary to withstand the service pressure wthinthe casing 1. The minimum'depth of groove' required is determined by thecharacter of the 'metal from which the tybe sheet is made, but in thecase of the isual steel tube sheet, the.

third of the thickness of'the tube sheet.

have shown a groove of`rectangul-ar section, it will be obvious that theinvention can be carried into effect by the use of grooves of othersectional form.

A second groove 18 is referably provided i 4 between the quarter hea ers11 and 12 for the purpose of preventing the transnission of fibreStress' from the surface under any one header from being transmitted tothe surface ,experience that the most satisfactory results are obtainedif each individual header secured to a given tube sheet. is separated bymeans of a groove in the face of the tube sheet from all other headerssecured" thereto.

It is to be understood, however, that such separation of each header yfrom all other headers secured to the same tube sheet is not in allcases necessary to secure the desired object of the invention, and it isfurther to be understood that the invention is in no way limited to theform of apparatus chosen hereinfor illustrative purposes but may beapplied equally well to any form of apparatus where a plurality ofheaders are secured to an integral tube sheet.

I claim:

1. As a new article of manufacture, a tube sheet provided with aplurality of spaced groups of .tube holes and a*groove in one face ofthe tube sheet located between and separating two of the groups of tubeholes.

2. As a new article of manufacture, a tube sheet r provided with agenerally circular group of tube holes spaced along a diameter of thecircle to form separated generally semi-circular tube groups and agroove in one face of the tube sheet along the diametral space betweensaid tube grooves.

3. As a new article of manufacture, an in tegral metallic tube sheetprovided with three spaced groups of tube holes, one of said 'groupsbeing generally semi-circular in outgroove in one face ofthe headerlocated on the diameter of the tube sheet separating the semi-circulargroup of tube holes from the quarter-circular groups of tube holes.

4. As a new article of manufacture, an integral metallic tube sheetprovided with three spaced groups of tube holes, one of said groupsbeing generally semi-circular i-n outline with the other two of saidgroups being "generally quarter-circular. in outline, a

groove in one face of the header located on the diameter of the tubesheet separating the semi-circular group of tube holes from the quartercircular groups of tube holes, and a groove in the same face of theheader located on the radius separating the quarter circular groups oftubes.

5. In apparatus of the class described, a plane metallic tube sheet, aplurality of spaced groups of tubes secured therein, a plurality ofheaders secured to one face of iso said tube sheet, and -a groove in theface of i the tube sheetto which the headers are secured, said groovelying betweenand separatingtwo of said headers.

6. n tube sheet, headers bolted to one face of said 'tube sheet andgrooves in the face of the tube 'sheet to which the headers are bolted,said apparatus f the class described, a

grqoves Being located so that each heaer is separated by a groove fromeach of the other headers.

7. In apparatusof the class described, a tube sheet having a plane face,two heaers bolted to said face, each of said heaers having a straightwall relatively' closely space& from and substantially Parallel to acorre sponding wall of the other header, and a straight groove cut insaid face between said walls.

8. In apparatus of the class described, a tube sheet having a, planeface, three headers bolted to said face, each of said headers hav ing astraight wall relativel closely space@- from and substantially para leito a straight wall of eachof the remaining headers, and straight groovescut in said face between each pair of adjacent header WaHs.

CHARLES W. GORDQN.,

